The death toll when Rwandan police broke up a crowd demonstrating against a cut in food rations has reached 11, the United Nations refugee agency says.
Police had reported five Congolese refugees were killed and more than 20 injured in the Thursday incident.
It followed days of sit-ins against the reduction in food aid at Kiziba refugee camp in western Rwanda.
The UNHCR released a statement saying 11 died at two locations.
"This tragedy should have been avoided and the disproportionate use of force against refugees is not acceptable, UNHCR external relations officer Daniela Ionita said.
"UNHCR calls on the authorities to refrain from use of force and to investigate circumstances of the tragic incidents. The UN Refugee Agency is shocked and disturbed by the loss of refugee lives," UNHCR said.
Many others were injured - including members of the police force and UNHCR employees.
Eight of the refugees died in Karongi town, where thousands had gone to protest at the offices of World Food Programme, and three died inside Kiziba Camp.
The situation at Kiziba camp, which hosts over 17,000 Congolese refugees, was by Monday reported calm. The UNHCR was expected to resume aid work in the camp Tuesday.
Over 173,000 Congolese and Burundian refugees are in six camps in Rwanda, many have been there for over 20 years.
The World Food Programme reduced food rations in the camps by 10 per cent in November 2017 and 25 per cent in January 2018 due to a shortage in funds.
Under-funding has severely affected humanitarian operations in Rwanda. UNHCR's 2018 appeal for US$98.8 million to support refugees in Rwanda is only 2 per cent funded.
The UNHCR, said it has received just two per cent of the $98.8 million (80 million euros) it needs this year to look after the refugees.